The Question:

When did the first case of hijacking occur?

The Answer:

We assume you're wondering about airplanes. In that case, the
more correct question is, "When was the first "skyjacking?"

Although used interchangeably today, the word "hijacking" hasn't always applied to
airplanes. In fact, the term originated the 1920s and 30s in the U.S.
when gangsters were seizing trucks or other vehicles from America's
streets.

The first recorded skyjacking of an airplane took place on Feb.
21, 1931 at the city of Arequipa, Peru when a group of
rebel soldiers in Peru forced two American pilots to fly them about
and drop propaganda leaflets over Lima. The pilots refused and the
rebels ended their seizure on March 2, without any damages to the
plane.

The first case of skyjacking within the United States occurred
on May 1, 1961, when a man forced a commercial airliner enroute from
Miami to Key West, Fla., to detour to Cuba. It was the first of four
flights diverted to Cuba that year.